High Performance Perylenediimide-Based Copolymers and Thin Films Made Therefrom

The paper describes the synthesis and characterization of three copolymers containing perylenediimide units and other chromophores in the main chain, as well as various flexible groups as siloxane, hexafluoroisopropylidene or ether, with emphasis on their thermal and photo-optical properties. Very thin copolymer films were obtained from these polymers with smooth and homogeneous surfaces that are self-organized into vertically segregated structures. Upon irradiation with light of different wavelengths the polymers in solution showed photoluminescence maxima in the UV, blue or green-yellow spectral range. In solid state only a weak emission in the UV domain occurred due to aggregation of perylenediimide cromophores which leds to fluorescence quenching. The FRET phenomenon between oxadiazole to perylene-diimide chromophores was observed to occur for which the oxygen bridge appear to be responsible. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3507

Biomimetic artificial water channel membranes for enhanced desalination

Inspired by biological proteins, artificial water channels (AWCs) can be used to overcome the performances of traditional desalination membranes. Their rational incorporation in composite polyamide provides an example of biomimetic membranes applied under representative reverse osmosis desalination conditions with an intrinsically high water-to-salt permeability ratio. The hybrid polyamide presents larger voids and seamlessly incorporates I–quartet AWCs for highly selective transport of water. These biomimetic membranes can be easily scaled for industrial standards (>m2), provide 99.5% rejection of NaCl or 91.4% rejection of boron, with a water flux of 75 l m−2 h−1 at 65 bar and 35,000 ppm NaCl feed solution, representative of seawater desalination. This flux is more than 75% higher than that observed with current state-of-the-art membranes with equivalent solute rejection, translating into an equivalent reduction of the membrane area for the same water output and a roughly 12% reduction of the required energy for desalination

Tunable membranes incorporating artificial water channels for high-performance brackish/low-salinity water reverse osmosis desalination

Membrane-based technologies have a tremendous role in water purification and desalination. Inspired by biological proteins, artificial water channels (AWCs) have been proposed to overcome the permeability/selectivity trade-off of desalination processes. Promising strategies exploiting the AWC with angstrom-scale selectivity have revealed their impressive performances when embedded in bilayer membranes. Herein, we demonstrate that self-assembled imidazole-quartet (I-quartet) AWCs are macroscopically incorporated within industrially relevant reverse osmosis membranes. In particular, we explore the best combination between I-quartet AWC and m-phenylenediamine (MPD) monomer to achieve a seamless incorporation of AWC in a defect-free polyamide membrane. The performance of the membranes is evaluated by crossflow filtration under real reverse osmosis conditions (15 to 20 bar of applied pressure) by filtration of brackish feed streams. The optimized bioinspired membranes achieve an unprecedented improvement, resulting in more than twice (up to 6.9 L center dot m-2 center dot h-1 center dot bar-1) water permeance of analogous commercial membranes, while maintaining excellent NaCl rejection (>99.5%). They show also excellent performance in the purification of low-salinity water under low-pressure conditions (6 bar of applied pressure) with fluxes up to 35 L center dot m-2 center dot h-1 and 97.5 to 99.3% observed rejection

Hydrophobic polyamide nanofilms provide rapid transport for crude oil separation.

Hydrocarbon separation relies on energy-intensive distillation. Membrane technology can offer an energy-efficient alternative but requires selective differentiation of crude oil molecules with rapid liquid transport. We synthesized multiblock oligomer amines, which comprised a central amine segment with two hydrophobic oligomer blocks, and used them to fabricate hydrophobic polyamide nanofilms by interfacial polymerization from self-assembled vesicles. These polyamide nanofilms provide transport of hydrophobic liquids more than 100 times faster than that of conventional hydrophilic counterparts. In the fractionation of light crude oil, manipulation of the film thickness down to ~10 nanometers achieves permeance one order of magnitude higher than that of current state-of-the-art hydrophobic membranes while retaining comparable size- and class-based separation. This high permeance can markedly reduce plant footprint, which expands the potential for using membranes made of ultrathin nanofilms in crude oil fractionation

Diaquabis(pyridine-2-carboxylato-κ2N,O)zinc dimethylformamide hemisolvate

In the title compound, [Zn(C6H4NO2)2(H2O)2]·0.5C3H7NO, the ZnII ion is coordinated in a distorted octahedral N2O4 environment by two N,O-chelating pyridine-2-carboxylate ligands and two cis water molecules. The chelating pyridine-2-carboxylate ligands create two five-membered Zn/N/C/C/O rings, which form a dihedral angle of 86.4 (2)°. In the crystal, O—H...O hydrogen bonds link the complex molecules into a two-dimensional network parallel to (100). The dimethylformamide solvent molecule is disordered about a twofold rotation axis

Unprecedented Coordination Compounds with 4,4′-Diaminodiphenylethane as a Supramolecular Agent and Ditopic Ligand: Synthesis, Crystal Structures and Hirshfeld Surface Analysis

In this pioneering research, mononuclear coordination complexes and coordination polymers were obtained using the conformationally flexible ditopic ligand 4,4′-diaminodiphenylethane and different metal salts (nitrates, sulfates, tetrafluoroborates and perchlorates). Seven new products, including the mononuclear complexes [Cd(2,2′-bpy)3](ClO4)2](dadpe)(4,4′-bpy) (1), [Ni(dadpe)2(H2O)4](SO4).H2O (2), one-dimensional coordination polymers {[Zn(NO3)(dadpe)(dmf)2](NO3)}n (3), {[Cd(2,2′-bpy)2(dadpe)](ClO4)2}n (4), and two-dimensional coordination polymers, {[Cd(4,4′-bpy)2(H2O)2](ClO4)2(dadpe)(EtOH)2}n (5), {[Co(4,4′-bpy)2(H2O)2](BF4)2(dadpe)(EtOH)2}n (6) and {[Cd(adi)(dadpe)](H2adi)}n (7), (dadpe=4,4′-diaminodiphenylethane, 2,2′-bpy=2,2′-bipyridine, 4,4′-bpy=4,4′-bipyridine, H2adi=adipic acid) were produced. The synthesized compounds were characterized by FTIR and single-crystal X-ray diffraction analyses. The dadpe was recorded as a neutral guest in the crystals of mononuclear complex 1 and in coordination polymers 5 and 6. In compound 2, two dadpe ligands coordinate in a monodentate mode and occupy two trans-positions in the [Ni(H2O)4(dadpe)2]2+ octahedral complex cation. Coordination polymers 3 and 4 represent single chains originating from dadpe as a bidentate linker in both. The H-donor’s possibilities of amino groups were utilized in the interconnection of coordination chains into H-bonded networks via NH(NH2)···O hydrogen bonds. The isostructural coordination polymers 5 and 6 comprise similar cationic square grids [M(4,4′-bpy)2(H2O)2]2+ [M=Cd (5), M=Co (6)], with sql topology balanced by the charge-compensated anions, while dadpe and EtOH as neutral guests are situated in the interlayer space. The neutral 2D coordination network in 7 with the sql topology originates from both adi and dadpe linkers as bidentate-bridging ligands, and the neutral H2adi is entrapped as a guest in crystal lattice. The impact of different types of intermolecular interactions was evaluated by Hirshfeld surface analysis

Six Flexible and Rigid Co(II) Coordination Networks with Dicarboxylate and Nicotinamide-Like Ligands: Impact of Noncovalent Interactions in Retention of Dimethylformamide Solvent

Six mixed-ligand Co­(II) coordination polymers, {[Co­(adi)­(iso-nia)₂]·dmf}_<i>n</i> (<b>1</b>), [Co­(adi)­(iso-nia)₂]_<i>n</i> (<b>2</b>), {[Co₂(suc)­(ac)₂(iso-nia)₄]­[Co₂(suc)­(sucH)₂(iso-nia)₄]­·2dmf}_<i>n</i> (<b>3</b>), [Co­(adi)­(nia)₂]_<i>n</i> (<b>4</b>), {[Co­(bdc)­(nia)₂]­·dmf}_<i>n</i> (<b>5</b>), and {[Co­(mal)­(S-nia)­(H₂O)]·dmf}_<i>n</i> (<b>6</b>), were synthesized and characterized by single crystal X-ray analysis. They are based on four dicarboxylic acids, namely, malonic (H₂mal), succinic (H₂suc), adipic (H₂adi), and 1,4-benzenedicarboxylic (H₂bdc) acids, as well as three nicotinamide-like ligands, isonicotinamide (iso-nia), nicotinamide (nia) and thionicotinamide (S-nia). Compounds <b>1</b>, <b>2</b>, and <b>3</b> represent one-dimensional coordination polymers, whereas <b>4</b>, <b>5</b>, and <b>6</b> exhibit two-dimensional structures. The coordination arrays in <b>1</b>–<b>5</b> are built from the similar [Co₂(COO)₂] binuclear clusters, while framework <b>6</b> is based on mononuclear metal nodes. All crystal lattices are supported by hydrogen bonding with nicotinamide-like ligands acting as pillars or dangling terminal ligands. Four crystal lattices <b>1</b>, <b>3</b>, <b>5</b>, and <b>6</b> host dmf solvent via NH···O hydrogen bonding and π–π stacking interactions with the coordination networks. Details of the reversible dmf release–uptake by <b>1</b> and <b>2</b>, and contribution of hydrogen bonding in stabilization of the solvent-free structures <b>2</b> and <b>4</b> are discussed. All new solids were characterized by IR spectroscopy and thermogravimetric analysis, while magnetic measurements are reported for compounds <b>1</b>, <b>5</b>, and <b>6</b>. The magnetic data show the typical behavior of Co­(II) ions originating from pronounced zero-field splitting within the ground state with contributing effects from weak antiferromagnetic exchange interactions

From pink to blue and back to pink again: changing the Co( ii ) ligation in a two-dimensional coordination network upon desolvation

Heating of a pink two-dimensional Co(II) coordination network {[Co2(μ2-OH2)(bdc)2(S-nia)2(H2O)(dmf)]·2(dmf)·(H2O)}n (1) built from 1,4-benzenedicarboxylic acid (H2bdc) residues and thionicotinamide (S-nia) ligands initiates a single-crystal-to-single-crystal transition accompanied by removal of both coordinated and co-crystallized solvents. In the dry blue form, [Co(bdc)(S-nia)]n (dry_1), the Co(II) centers changed from an octahedral to a square pyramidal configuration